Electronic devices, e.g., digital cameras, docking stations, printers, computers, handheld appliances, scanners, etc., are susceptible to electronic component disruption by the introduction of ESD events, commonly referred to as static electricity discharges. ESD events are generally in the range of several or even tens of thousands of volts per discharge. While each discharge is extremely short in duration, such potential differentials can cause disruptions to electronic devices such as loss of memory, device reset or even irreparable physical damage through the fusing or rupture of device components. To avoid such disruptions, many devices contain some form of ESD suppression to protect internal components from a received discharge.
One method of ESD suppression involves adding components between the ESD introduction path and the ground plane. Common ESD suppression components include diodes, zener diodes, resistors and capacitors to route or direct any electrical surge away from the protected components. However, these components remain an active portion of the circuitry. As such, ESD suppression in this manner can impair performance of the protected circuitry or otherwise lead to signal loss.
Another method of ESD suppression is to place a spark gap between the ESD introduction path and a ground plane. The spark gap is typically designed for a threshold or breakdown voltage such that discharges exceeding this voltage arc across the gap and are conducted to ground. Such methods of ESD suppression have been incorporated onto printed circuit boards (PCBs). However, it is challenging to maintain tight tolerances in the separation between the introduction path and the ground plane. Designers may thus specify a separation that is larger than desired in order to avoid shorting the introduction path to the ground plane. Larger separations lead to higher breakdown voltages, which may limit the protection provided.
For the reasons stated above, and for other reasons stated below that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternative apparatus for suppression of ESD events.